- Contest Winner Cameo: There is a set of stairs near Clayface's cell that lead to a cell where a creepy prisoner is held. He is actually the winner of a GameSpot contest in which the winner got their face and name put in the game. His name, Luke Oliver, shows up on the Joker's party list.
- Cross-Dressing Voices: Kimberly Brooks voices Young!Bruce. Yes, you heard right, Ashley f'n Williams was the goddamn Batman.
- End of an Era: To date, this is the final time Arleen Sorkin has voiced Harley Quinn. Following this, she has mainly been voiced by Tara Strong, with other actresses like Hynden Walch, Laura Bailey, Melissa Rauch, Kaley Cuoco, among others.
- Executive Meddling: Producers forced Kevin Conroy to use his regular speaking voice for this game. He'd go back to using his trademark gruff Batman voice in the two sequels.
- Follow the Leader:
- The Captain America: Super Soldier game copies this game's basic fighting engine (though not quite as well), with a counter, dodge, stun, and attack button. It also tries to copy the Metroidvania style layout, but to less success. Still, imitation is the sincerest form of flattery...
- The movie-licensed game based on The Amazing Spider-Man 2012 film goes further in copying Arkham Asylum. In addition to having the same combat system as Arkham Asylum, there are also patient interview tapes (redubbed "audio evidence tapes") and a level where Spider-Man rescues doctors from escaped patients in an asylum. The devs openly admit they used Arkham Asylum's combat because they felt it was a good fit for Spider-Man.
- Middle-earth: Shadow of Mordor drew its combat from the Arkham games, and they also sought to make a licensed product entirely separate from the movies and more suited to the videogame medium, which they saw Arkham Asylum as an example of it being done right.
- The combat system in the Mad Max licensed game was frequently compared to the combat in this game.
- In a less flattering example, Ride to Hell: Retribution used a greatly simplified version of the combat system.
- Mid-Development Genre Shift: Arkham Asylum was going to be a Rhythm Game, where the fight scenes would become upbeat 2D dance scenes and you would have to press the right colored buttons on cue, almost like in Rock Band. This whole idea came from these two stories from the developers and from director Sefton Hill. You can still see traces of this in the freeflow combat sections, which do feel rather like a rhythm game at points.note
- Name's the Same: Jack White, Joker's alias, has quite the same name as John "Jack" Gillis of The White Stripes, who took the maiden name of "White" when he was once married to Meg White.
- Relationship Voice Actor:
- For fans of Batman: The Animated Series, including its spin-offs like Batman Beyond and the movies, in addition to Batman, Thomas Wayne, Joker, and Harley Quinn retaining their voice actors, Dr. Whistler is Catwoman, Oracle is Kathy Duquesne, and Dr. Young is Max Gibson.
- From The Avengers: Earth's Mightiest Heroes!, Young!Jim Gordon is Thor, Absorbing Man, and Surtur; Bane is the Hulk, Red Hulk, the Thing, Graviton, Mandrill, Volstagg, Fernis, and Yon Rogg; the Riddler is Hank Pym and M.O.D.O.K.; Eddie Burlow is Hawkeye, Crimson Dynamo, Fandral, and Rattler, and Commissioner Gordon and Quincy Sharp are Ultron, Jasper Sitwell, and Professor Thornton.
- Role Reprise:
- From Batman: The Animated Series, Kevin Conroy reprises the roles of Batman and Thomas Wayne, Mark Hamill reprises the role of the Joker, and Arleen Sorkin reprises the role of Harley Quinn.
- In the French dub, several voice actors from previous adaptations reprised their roles here:
- Talking to Himself:
- Tom Kane is Commissioner Gordon and Quincy Sharp, and Mark Hamill is the Joker and Scarface.
- Steve Blum voices many incidental voices, so this is expected. It's first noticeable in the introductory sequence with the doctor yelling at a guard to take the Joker away after the Joker offends the doctor by offering to drop his pants.
- Wally Wingert voices not only the Riddler, but also the police officer who arrests him once you find all the Riddler trophies.
- Viral Marketing: Gotham City Municipal's Website, with a hidden Alternate Reality Game. Sadly seems to be offline now.
- Most of the dialogue from Harley Quinn's tapes is an almost word for word reproduction of Batman: The Animated Series' Paul Dini's original origin story for Harley Quinn, Mad Love.
- The Arkham Care tie-in website lists its partners as Wayne Enterprises for the computer and security systems and Ace Chemical Processing for pharmaeceuticals. The factory was the birthplace of the Joker, when he fell into a vat of acid that turned his hair green, and his skin chalk white. Probably.
Trivia / Batman: Arkham Asylum